The present invention generally relates to the sealing of two-piece capsules to avoid the unauthorized access to, and the leakage of, the sealed contents and, more particularly, to an apparatus for continuously sealing the filled capsules of two-piece construction.
It has long been a general notion that hard-gelatin capsules each made in two sections, cap and body, were to be used exclusively for containing powdery or grainy pharmaceutical product whereas soft-gelatin capsules are used for containing any one of the powdery, grainy and liquid pharmaceutical products. However, attempts to use the hard-gelatin capsules for filling liquid pharmaceutical products have relatively recently been made successfully and pharmaceutical hard-gelatin capsules containing liquid or liquid-containing medicines are currently commercially available along with those containing powdery and grainy ones. This is true not only of the pharmaceutical industry, but also of the food or confectionary industry.
As is well known to those skilled in the art, the closed capsules, i.e., the complete capsules wherein the capsule caps have been mounted on the respective capsule bodies with the contents filled therein, are, before they are packaged in unit number or shipped, sealed for the purpose of avoiding either or both the unauthorized access to the contents and the leak of the contents, particularly if they are liquid, from the closed capsules. Conventionally employed methods for sealing the two-piece capsules include, for example, the employment of what may be possibly termed a "click-on" system wherein each capsule body is formed with either one of a radially outwardly extending circumferential projection and a radially inwardly extending circumferential recess while the respective capsule cap is formed with the other of the circumferential projection and recess so that, when the capsule cap is mounted on the capsule body to provide the complete capsule, the circumferential projection can be clickedly received in the circumferential recess; the application of water to the overlapping joint of each closed capsule to permit the open end of each capsule cap to stick exteriorly to the open end of the respective capsule body upon drying; and the application of a gelatin solution to form a binder layer at the overlapping joint of each closed capsule.
The present invention is essentially concerned with the handling of the two-piece capsules each comprised of a cup-like body and a cap, regardless of the contents filled therein, with a liquid binder such as, for example, a gelatin solution, to provide the fluid-tightly sealed capsules.
A conventional capsule sealing apparatus including a gelatin solution applicator operates on an intermittent basis. In other words, in the conventional apparatus, the closed capsules are intermittently transferred through a binder applying zone where the applicator unit is installed. Accordingly, the conventional apparatus has been found disadvantageous in that the capsule handling capacity is limited with a relatively increased processing time required to complete the sealing of the closed capsules. Moreover, not only does the intermittent transfer system constitute a cause of noise generation, but also the design and nature of the apparatus make it difficult to inspect the successively sealed capsules.